High reliability connectors such as those used in defense applications, have generally included housing layers with contact-receiving holes. Clips lying in the holes hold the contacts against rearward mating forces while allowing the contacts to be replaced by the use of special tools. The use of clips to retain contacts has several disadvantages. If a clip fails during mating of contacts, when the maximum force is applied to the clips, a contact can be pushed out of the insulative layer, possibly damaging circuitry to which the tail or termination end of the contact is attached. In addition to the reliability problem, clips are expensive. A system for retaining contacts which avoided the use of clips while providing high reliable resistance to mating forces and moderately high resistance to unmating forces for replaceable contacts, would be of considerable value.